The applications of flexible materials to display devices and/or thin-film solar cells have been actively studied. To manufacture these electronic devices, it may be advantageous to use an organic semiconductor instead of general an inorganic semiconductor. Thus, the organic semiconductor is very attractive in the electronic devices. An organic semiconductor device is a semiconductor device that uses an organic semiconductor material as a channel. However, since the organic semiconductor is sensitive to the external environment as compared with the inorganic semiconductor, there is a need for improving electrical characteristics and durability of the organic semiconductor device.